Enhanced optical properties and photodetection behavior of ZnS thin film deposited by electron beam evaporation upon doping with europium oxide

Abstract In the present study, pure zinc sulfide, zinc sulfide annealed at 500 °C, and zinc sulfide-europium oxide nanocomposite were deposited on a silicon substrate by the electron beam deposition method and their structural and optical properties and detection behavior were investigated. Zinc sulfide nanoparticles were synthesized by chemical deposition and annealed at 500 °C. Their structural and phase properties were studied by X-ray diffraction (XRD), indicating formation of wurtzite phase on the zinc sulfide structure. Europium oxide was added to the composite as a reinforcing phase at 5 wt% by the chemical deposition method. The XRD pattern demonstrated that there was a good intensity of the europium oxide peaks along the zinc sulfide peaks in the nanocomposite. Scanning electron microscopy showed that the zinc sulfide layers deposited by the electron beam deposition method had a good uniformity and that the europium oxide particles were presented in the layers with good dispersion. The energy dispersive spectroscopy showed that the stoichiometry of the zinc sulfide deposited on the silicon substrate did not change with the electron beam deposition method and confirmed the presence of europium oxide in the layers. Photoluminescence spectroscopy results showed that with the addition of europium oxide to the zinc sulfide, the intensity of the peaks increased compared to pure zinc sulfide and annealed zinc sulfide at 500 °C, which showed an increase in the rate of electron-hole generation. This increase in electron-hole generation was also demonstrated in the optoelectrical properties of the fabricated photodetectors. The sensitivity of the detector under UV illumination for pure zinc sulfide and annealed sample at 500 °C was 10.30 and 15.29, respectively. But for the sample containing europium oxide, the sensitivity increased to 42.76.